ANNOTATIONS AND ADDITIONS. 245 



E. Plain of the Atrio del Cttvallo. 



Toises. Eng. ft. 

 Humboldt, 1822, barometric . . . .403 2577 



F. Foot of the cone of ashes. 



Toises. Eii. ft. 

 Gay-Lussac, Leopold von Buch, and Humboldt, 



1805, barometric 370 2366 



Humboldt, 1822, barometric . . . . 388 2481 



G. Hermitage del Salvatore. 



Toises. Eng. ft. 

 Gay-Lussac, Leopold von Buch, and Humboldt, 



1805, barometric 300 1918 



Lord Minto, 1822, barometric .':< U it^f t /.'i 307'9 1969 

 Humboldt, 1822, barometric repeated . t^iciv-i; 3087 1974 



Part of my measurements have been printed in Monticelli's 

 Storia de' fenomeni del Yesuvio, avvenuti negli anni 1821- 

 1823, p. 115 ; but the neglected correction for the height 

 of the mercury in the cistern has somewhat disfigured the 

 results as there published. When it is remembered that 

 the results given in the above table were obtained with 

 barometers of very different constructions, at various hours 

 of the day, with winds from very different quarters, and on 

 the unequally heated declivity of a volcano, in a locality in 

 which the decrease of atmospheric temperature differs 

 greatly from that which is supposed in our barometric 

 formulae, the agreement will be found to be as great as 

 could be expected, and quite satisfactory. 



My measurements in 1822, at the time of the Congress 

 of Yerona, when I accompanied the late King of Prussia to 



